In practice, it is known that, for example in the production of sausage-shaped products, like sausages, filling material is fed by a filling machine through a filling tube of a clipping machine into a tubular or bag-shaped packaging casing which is stored on the filling tube and which is closed at its front end, i.e. the end pointing in the feeding direction of the filling material by a closing clip. The tubular or bag-shaped packaging casing is pulled-off from the filling tube while being filled by the feeding pressure. A casing brake is positioned in the region of the front end of the filling tube, i.e. the end of the filling tube facing in feeding direction, in order to apply a frictional force to the tubular or bag-shaped packaging casing while being pulled-off from the filling tube.
After a predetermined volume of filling material has been filled into said tubular or bag-shaped packaging casing, a displacer arrangement with a first and a second displacer unit which can each be formed by a pair of reversibly moveable displacement elements, gathers the filled tubular or bag-shaped packaging casing and shapes a plait-like portion thereto. The clipping machine then places and closes at least one closing clip at the plait-like portion forming the rear end of the sausage shaped product, i.e. the end pointing against the feeding direction by respective closing tools which are reversibly movable towards the plait-like portion.
In known clipping machines, the casing brake is positioned a distance upstream the front end of the filling tube such that the brake element of the casing brake is positioned on the filling tube in order to enable the casing brake to apply a defined frictional force to the tubular or bag-shaped packaging casing, and to provide a space between the inner surface of the tubular or bag-shaped packaging casing and the outer surface of the front end of the filling tube into which filling material may be displaced, particularly during the closing operation.
Such a clipping machine is known from EP patent application 2 323 491 in which the casing brake is arranged on the filling tube in a fixed position during the production process. For refilling tubular casing onto the filling tube, the casing brake may be removed from the filling tube by pivoting the filling tube together with the casing brake out of its working position and by reversibly drawing-off the casing brake assembly from the filling tube.
From EP patent application 1 764 000, a clipping machine is known which includes a casing brake having a holder for holding a brake ring. The holder together with the brake ring is coupled to a drive, and is reciprocally movable along the filling tube of the clipping machine by said drive. During the closing operation, particularly during the forming of a plait-like portion to the filled tubular casing, the brake ring is moved along the filling tube opposite to the feeding direction, in order to provide additional space between the tubular casing and the outer surface of the filling tube for accommodating the filling material displaced while gathering the filled tubular casing and forming a plait-like portion thereto. After the closing operation has been finished, the holder is moved in the feeding direction into its starting position close to the front end of the filling tube.
Dependent on the kind of filling material, and further dependent on the size of the available additional space between the inner surface of the tubular or bag-shaped packaging casing and the outer surface of the filling tube in the region of its front end, a portion of the filling material which enters said additional space, may remain there, e.g. adhering at the filling tube. Thereby, the quality of the sausage-shaped products may be affected.
It is an object of the present invention to provide a method for producing sausage-shaped products and a machine, like a clipping machine, which overcome the above mentioned drawbacks, and by means of which sausage-shaped products of high quality may be produced.